SPIKE: Create a manual for auditors

[PaulMakinMojaloop]

As documented in issue #3914, it is apparently possible for an operator to "kill" the audit process, and then carry out auditable activities without a record being created.

However, investigations subsequently found that this is mistaken, and that the activities will reappear in audit logs when the audit process returns.

The purpose of this spike is to make sure this fact isn't forgotten, and makes its way into an documentation aimed at auditors.